Water levels Tide variations in the Kattegatt Strait and thus in Gothenburg are small. There is only a 20 cm difference between the highest high water (HHW) and the lowest low water (LLW). However, the variations in water levels in Gothenburg and the fairways outside can vary considerably due to other factors, such as atmospheric pressure and winds.

Atmospheric pressure and seawater level The higher the atmospheric pressure at the location, the lower the water level. A rule of thumb is that an increase in atmospheric pressure of 1 millibar (hPa) lowers the water level by 1 cm. The lower the atmospheric pressure, the higher the water level.

Winds and sea levels Strong winds blowing from the south-west to the west and north-west raise the water level along the west coast and at the port, resulting in high water conditions. Easterly winds cause the water level to fall, resulting in low water conditions.

The greatest variations in water levels arise when the moon, atmospheric pressure and winds interact. When this happens, the difference between the highest water level and the lowest water level can be around 280 cm in Gothenburg although this is highly unusual.

Typical water levels in cm at the Tor Harbour in Gothenburg in relation to the mean water level (MW) in Gothenburg

Observed rel. MW

RH100

RH70

GH88 (m)

Year

HHW

169

149

158

11.65

1914

MHW

92

72

81

10.88

MW

0

-20

-11

9.96

MLW

-60

-80

-71

9.36

LLW

-111

-131

-122

8.85

1976

DW

280

280

280,00

2.80

The average values refer to 2013. Land rise coefficient: 0.18 cm/year

HHW = Highest high water level MHW = Medium high water level (average highest water level over the years) MW = Mean water level (= 0) MLW = Medium low water level (average lowest water level over the years) LLW = Lowest low water level DW = Difference between the highest and lowest water level